Characterization of benzoxazine resins for brake pad friction materials manufacturing

Abstract

Phenolic resins are the most commonly used binders in brake pads for automotive disc brake systems owing to their affordability and thermal properties. However, they also show some limitations related to their crosslinking mechanism. Benzoxazine resins present themselves as possible alternatives for this application by providing enhanced thermal properties as well as other industrially attractive characteristics such as lower moisture absorption and unlimited shelf life. This study investigates the thermal properties of two different benzoxazine resins, with the aim of assessing their capabilities as binder for brake pad and of understanding how to process them in order to actually employ them as such. DSC, TGA, hardness and tribological analyses were carried out on neat resin samples and on friction materials containing them as binder. The presence of several concurring reactions was detected during the crosslinking reaction of benzoxazine resins. The benzoxazine resins showed lower mass loss respect to a phenolic resin in the temperature range of interest for commercial brake pads application. Friction material containing benzoxazine resin binder showed promising tribological results.

Corrosion Stiction in Automotive Braking Systems

“…Gurunath et al [ 17 ] showed that the ring-opening polymerization of polybenzoxazines can be employed for the formation of friction materials with unlimited shelf life, low moisture absorption, and minimal volumetric change, with low or no formation of byproducts in the curing reaction. Carlevaris et al [ 18 ] showed that bisphenol A and bisphenol F benzoxazine-based resins can significantly reduce particulate emissions as compared to traditional binders while preserving their tribological properties.…”

A Study on Characteristics of Brake Pad Composite Materials by Varying the Composition of Epoxy, Rice Husk, Al2O3, and Fe2O3

“…The thermal decomposition temperatures produced in this study are higher than the results of previous studies. Carlevaris et al made brake pads using benzoxazine with the resulting thermal decomposition occurring between 164.4 °C and 246.5 °C [73].…”

Molecular‐level fabrication strategies for the POSS cross‐linked polybenzoxazines

“…Depending on the backbone chemistry of BZ can provide PBZ with not only excellent fire resistance properties and char yield, but also near‐zero volumetric change, low smoke, high T g along with excellent physical electrical performance 14–16 . So, PBZ is widely applied for printed circuit boards (PCB), 17 friction material, 18 and outer protection of aircraft 19 …”

“…[11][12][13] Depending on the backbone chemistry of BZ can provide PBZ with not only excellent fire resistance properties and char yield, but also near-zero volumetric change, low smoke, high T g along with excellent physical electrical performance. [14][15][16] So, PBZ is widely applied for printed circuit boards (PCB), 17 friction material, 18 and outer protection of aircraft. 19 Synthesis of functionalized benzoxazine POSS nanocomposites was reported through alkynyl group click reaction, 20 thiol-ene click reaction, 21 and curing reaction.…”